Effect of sodium bicarbonate and varying concentrations of sodium chloride in brine on the liquid retention of fish (Pollachius virens L.) muscle.

BACKGROUND: Negative health effects associated with excessive sodium (Na) intake have increased the demand for tasty low-Na products (<2% NaCl) rather than traditional heavily salted fish products (∼20% NaCl). This study investigates the causes of improved yield and liquid retention of fish muscle brined with a combination of salt (NaCl) and sodium bicarbonate (NaHCO3 ). RESULTS: Water characteristics and microstructure of saithe (Pollachius virens L.) muscle brined in solutions of NaCl and NaHCO3 or NaCl alone were compared using low-field nuclear magnetic resonance (LF-NMR) T2 relaxometry, microscopy, salt content, liquid retention and colorimetric measurements. Saithe muscle was brined for 92 h in 0, 30, 60, 120 or 240 g kg(-1) NaCl or the respective solutions with added 7.5 g kg(-1) NaHCO3 . NaHCO3 inclusion improved the yield in solutions ranging from 0 to 120 g kg(-1) NaCl, with the most pronounced effect being observed at 30 g kg(-1) NaCl. The changes in yield were reflected in water mobility, with significantly shorter T2 relaxation times in all corresponding brine concentrations. Salt-dependent microstructural changes were revealed by light microscopy, where NaHCO3 supplementation resulted in greater intracellular space at 30 and 60 g kg(-1) NaCl. CONCLUSION: Sodium bicarbonate addition to low-salt solutions can improve yield and flesh quality of fish muscle owing to altered water mobility and wider space between the muscle cells.

Berry marinades enhance oxidative stability of herring fillets.

Marinating herring fillets in a 50 g/L powder of elderberry, cranberry, or black currant inhibited the oxidation of lipids and proteins and also the degradation of tocopherol. Cranberry and black currant appeared to be more efficient than elderberry in inhibiting the degradation of tocopherol and the formation of ammonium. Elderberry marinades provided the most significant color changes. The injection of fillets with a 5% salt solution resulted in significantly increased levels of carbonyls, ammonium, and biogenic amines, whereas formation of the volatile lipid compounds propanal, hexanal, 2-penten-1-ol, and 1-penten-3-ol was lowest in fillets marinated in black currant following injection of the salt solution. All marinade treatments resulted in a significantly decreased liquid holding ability, coinciding with a lower muscle pH. It is concluded that marinating herring fillets in solutions containing berry powder can enhance the quality and shelf life of the fillets and simultaneously provide the fillets with natural antioxidants beneficial for consumers.